value1,value2,value3
apple,0,0
peach,0,0

##</code><code>##

use AnyData;

$testDB = adTie(
    'CSV',
    "test.db.csv",
    'u',
    { col_names=>'value1,value2,value3' },
    { key=>'value1'}
);

$testDB->{{value1=>"apple"}}={value2=>"yes"};

##</code><code>##

value1,value2,value3
apple,0,0
peach,0,0
apple,yes,0